To supply natural gas, in particular compressed natural gas (CNG), systems are necessary which are adapted to the particular motor vehicle and in which appropriate openings for the installation of valves or fastening points for the holders of a fuel distribution rail are necessary on the corresponding intake module, for example. Thus, a vehicle-specific adaptation is necessary. Cost-effective retrofit kits for motor vehicles, which are driven by gasoline and which retrofit these for a CNG operation, mostly fall short of the quality which is particularly necessary for emerging countries.